Water and air cooled electromagnet



Oct. 3, 1933. F. R JOHNSON 1,929,187

WATER AND AIR COOLED ELECTROMAGNET Filed Sept. 24, 1930 Patented Oct. 3, 1933 WATER AND AIR COOLED ELECTROMAGNET Fred R. Johnson, Hamburg, N. Y., assignor to The Exolon Company, Blasdell, N. Y., a corporation of Massachusetts Application September 24, 1930 Y Serial No. 484,119

Claims.

, structed and arranged as to permit continuous operation thereof without danger of overheating or charring the insulation of the magnet winding and thus short circuiting the magnet.

In accordance rwith my general concept, the magnet is cooled by circulating both water and air between the core and the windings of the magnet, and to this end, the magnet is so constructed as to insure the most efficient circulation of the cooling water and air. In accomplishing this result, I utilize the spaces between the concentric turns or layers of the winding as circulating channels along which the cooling air may be forced from both ends of the core towards the center where it escapes.

In order to insure a more thorough distribution of the cooling air through the winding and particularly a distribution thereof radially of the winding, I provide the winding itself, and especially the layer or layers nearest the core with a special form of insulating material.

To this end, such insulation may take the form of spaced insulating blocks of porcelain, silicon carbide, or other appropriate material having the property of being a good conductor for the heat generated in this region. Moreover, the spaces between the blocks in the several layers define circulation channels for the cooling air whereby to permit the air to reach all layers of the winding.

In addition the core is directly cooled by the circulation of a cooling stream of water from end to end thereof, such stream being carried by a water tube wound helically about the core itself.

As illustrating the principles involved, I describe and show in the accompanying specification and drawing a form of electromagnet which I have found highly satisfactory under actual service conditions.

In such drawing:

Fig. l is an elevation, partly broken away, of an electromagnet equipped in accordance with my invention.

Fig. 2 is a partial longitudinal section, the concentric layers of Winding 2 and the rope cover 4 of the magnet being shown however in elevation rather than in section for the sake of cleamess of illustration.

Fig. 3 is a transverse section on approximately the line 3--3 of Fig. 1, and

Fig. 4 is a similar section approximately on the line 4-4 of Fig. 2.

I have indicated at 1 the core of an Melectro- `(ci. 17a-21) magnet of standard type, but equipped with the special features constituting the present invention. This core may be made of any suitable magnetizable material as iron and in practice I have found that special Swedish electrical iron 00 of high purity, thoroughly annealed after machining, makes an especially satisfactory core.

As in any other electromagnet, the core 1 is provided with one or more layers or turns of winding. This may be simply copper wire 2 enclosed 55 in any usual insulating sheathing.

The winding 2 is laid about the core 1 between an inside iron tube 3 and an outside cover 4 of rope or other suitable protective and insulating material. This covering 4 is confined between the 70 end flanges 5 of brass or other non-magnetizable material of the core, and a pair of spaced central discs 6 of bre or other suitable insulating material.

Mounted in the spaces between the discs 6 is a 75 plurality of radially disposed spaced strips 7 of fibre or the like, which define exit openings for the cooling air which is circulated through the coil from each end thereof in the spaces between the superposed layers or turns of winding 2 and 30 which exhausts at the centre of the magnet through the spaces between said bre strips 7. The cooling air is forced through the magnet by any suitable blowers, the magnet being provided at each end with air inlets 8 and 9, and the end 85 flanges 5 being provided with concentric rows of spaced perforations 5 to permit the cooling air from ducts 8 and 9 to pass therethrough and along the magnet towards its center where it exhausts through a like series of concentric rows of perforations 6 formed in the discs 6 and out to atmosphere between the radial strips 7 spacing said discs 6. The strips '7 are disposed in nonblocking relation to said perforations 6' so as not to interfere with the free exhaust of the air at the center of the magnet. In its circulation through the spaces between the layers of winding, the cooling air absorbs and carries oif some of the heat generated by the magnet in operation.

'Iyhe successive layers of winding are spaced 100 from each other by concentric courses of spaced insulating blocks 10 of any suitable insulating material having the property of being a. good conductor of heat, as for example, porcelain or silicon carbide, the spaces 11 between such blocks con- 105 stituting air circulating openings through which air admitted at 8 and 9 into the spaces separating the superposed turns of winding may circulate radially of the magnet. The blocks 10 are relatively narrow strips. 'I'hey are laid axially on 110 EE e thsrealo windingtotheoentetofthecoilwhereit totheatmospherethrohperforations 0'.

than heretofore.

circulationofwatermaybeuponanywell system or the water may be allowed without any attempt at re-circulatheinsulationofthe charred, with resultant ofshortcircuitingthemmetorotherwiseoverheatingthessme.

While useful in any capacity where an electromagnet is commonly employed, my magnet is ratorsuchasisdescribedandillustratedinmy several prior applications for patent.

various modiiications in assembly, materials sndstructuremayall-beresoriedtowithinthe spiritandscopeofmyinventionasdeiinedbythe appendedclaims.

WhatIthereforeclaimanddesiretosecureby IettersPatentis:

1.Inanelectromagnet,acore.andawinding said core, the spaces between said layers of windingfromendtoendofthemagnet,andmesns orintroducingcoolingairintosuchchannels, water circulating tube disposed about the ofthe Inanelectromagnet, acore,andawinding form of a plurality of spaced layers about ,thespacesbetweensaidlayersofwinddesignedforuseinamsgnetic sepa-v ing constituting air circulation channels extendingfromendtoendof the megnet,andmeans at each end of the magnet for introducing cooling air into such channels. such air exhausting adiacentthe centreoi'themagnetthrougha common exhaust opening, and a water circulating tube disposed about the core of the magnet.

3. In anelectromsgnet.acorehaving ahelicai groove therein from end to end. a water circulating tube in said groove substantially ilush with thesuri'ace ofsaidcore,andawindingaboutsaid core.

4. In an electro-magnet, s core having perforatedendnangeaawindinginthefonnofa plurality of spaced layers about said core. and layers of insulation between said layers of winding.eachlayerofinsulation bavingthereina series of air circulating channels extending longitudinallyofthemagnet substantiallyfromend toendthereofandregisteringattheirouterends with the perforations of said end iianges, and meansateachendofthecoreiorintroducing cooling air through perforations of said iianges sndintoandthroughsaidchannelsforexhaust adjacent the center of the magnet. m

5. An electro-magnet as claimed in claim 4 v wherein the core adjacent its center is provided with a pair of smd discs having periorations registering with the inner ends oi.' said channels l whereby the airfrom said channelsmay exhaust m5 to atmosphere.

6.An electromagnet as claimed in claimt wherein the core adjacent its center is provided with a pair of spaced discs having periorations discsapartfromeachotherconsistofaseries of radial strips disposed in a non-blocking relato the perfor-ations thereof. In electromagnet. a core. a winding in of a plurality of spaced layers about and layers of insulation between said and circumferentially spaced sulation layer having a series of air circulating channels extending longitudinally of the magnet substantially from end to end thereof and registering with the perforations in the end anges of the magnet, means for introducing cooling air through said perforations of the flanges and into the outer ends of said channels, means adjacent the center of the core constituting an exhaust common to all of said channels, said last'named means consisting of a pair, of spaced discs adjacent the center of the core, each disc having concentric rows of spaced perforations registering with the inner ends of said channels' and a radial series of strips, spacing said pair of discs and disposed in non-blocking relation to said channels- 11. In an electro-magnet, a core having end anges, each flange provided with a plurality of concentric rows of spaced perforations, a core winding in the form of a plurality of spaced concentric layers about said core, and layers of insulation between said winding layers, each insulation layer comprising a plurality of blocks laid end-to-end on each winding layer and circumferentially spaced from each other to define a `series of air circulating channels extending longitudinally of the magnet substantially from end to end thereof and registering with the perforations in the end flanges of the magnet, means for introducing cooling air through said perforations of the flanges and into the outer ends of said channels, means adjacent the center of the core constituting an exhaust common to all of said channels, said last named means consisting of a pair of spaced discs adjacent the center of the core, each disc having concentric rows of spaced perforations registering with the inner ends of said channels, and a radial series of strips spacing said pairs of discs and disposed in non-blocking relation to said channels.

12. In an `electro-magnet, a core, a plurality of spaced layers of winding about said core, the spaces between said layers of winding constituting air circulating channels extending from end to end of the magnet, means at each end of the magnet for introducing cooling air linto such channels, and an exhaust for such cooling air consisting of a vpair of spaced discs intermediate of the en'ds of the magnet and having concentric rows of Y perforations registering with the inner endsrof such channels.

13. An electro-magnet as claimed in claim 12 wherein the means which space the pair of discs consists of a plurality of radial strips disposed in non-blocking relation to the perfoiations of said discsV 14. In an electro-magnet, a core, a core winding circumferentially wound about said core as a plurality of spaced concentric layers extending substantially from end to end of the magnet, a plurality of concentric layers of insulating material interposed between and spacing said layers vof vwinding material from each other, said insu- 

